Abstract:

The present invention relates electroluminescent devices, comprising a
compound of the formula (I), especially as host for phosphorescent
compounds. The hosts may function with phosphorescent materials to
provide improved efficiency, stability, manufacturability, or spectral
characteristics of electroluminescent devices.

Claims:

1. An electroluminescent (EL) device, comprising a compound of the formula
##STR00105## wherein A is a 5-, 6-, or 7-membered heteroaromatic ring,
containing at least one heteroatom selected from nitrogen, oxygen and
sulfur,Z1 is ##STR00106## NA1A1',
--P(═O)A4A4', or --SiA6A7A8,Z2 is
##STR00107## --NA2A2', --P(═O)A5A5', or
--SiA6'A7'A8',Ar and Ar' are independently of each other
C6-C14aryl which may optionally be substituted by one or more
groups selected from C1-C25alkyl which may optionally be
interrupted by --O--, or C1-C25alkoxy,R1, R2,
R3, R4, R5 and R6 are independently of each other
hydrogen, halogen, or an organic substituent, orR1 and R2,
R4 and R6, R2 and R3, R5 and R3 and/or
R5 and R6, which are adjacent to each other, together form an
aromatic or heteroaromatic ring or ring system which can optionally be
substituted,R7 is an organic substituent, wherein two or more
substituents R7 in the same molecule may have different meanings, or
can form together an aromatic or heteroaromatic ring or ring system, andx
is 0, or an integer of 1 to 5;A1, A2, A1' and A2' are
independently of each other a C6-C24aryl group, a
C2-C30heteroaryl group, which can optionally be substituted, or
a group ##STR00108## wherein BU is a bridging unit, A3 and A3'
are independently of each other a C6-C24aryl group or a
C2-C30heteroaryl group, which can optionally be substituted, or
A1 and A1' or A2 and A2' or A3 and A3'
together with the nitrogen atom to which they are bonded form a
heteroaromatic ring or ring systemA4, A4', A6, A7,
A8, A5, A5', A6', A7', and A8' are
independently of each other a C6-C24aryl group or a
C2-C30heteroaryl group, which can optionally be substituted.

2. The EL device according to claim 1, comprising a compound of formula
##STR00109## ##STR00110## R1 and R4 are independently of each
other hydrogen, halogen, C1-C18alkyl, C1-C18alkyl
which is substituted by E and/or interrupted by D, C1-C18
perfluoroalkyl, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, CN, or --CO--R28,R2, R3, R5
and R6 are independently of each other H, halogen,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C1-C18 perfluoroalkyl,
C6-C24aryl, C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, C7-C25aralkyl, CN, or
--CO--R28,R8 and R9 are independently of each other H,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C1-C18 perfluoroalkyl,
C6-C24aryl, C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, C7-C25aralkyl, CN, or --CO--R28,
orR8 and R9 together form a group ##STR00111## wherein
R206', R208' R205, R206, R207, R208,
R209 and R21 are independently of each other H,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C1-C18alkoxy, or
C1-C18alkoxy which is substituted by E and/or interrupted by D,
C1-C18 perfluoroalkyl, C6-C24aryl,
C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C7-C25aralkyl, CN, or --CO--R28,R10 is H,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C1-C18 perfluoroalkyl,
C6-C24aryl, C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, C7-C25aralkyl, or
--CO--R28,R8' and R9' are independently of each other H,
CN, --COOR27; --CONR25R26, C1-C18alkyl,
C1-C18alkyl which is substituted by E and/or interrupted by D,
C1-C18 perfluoroalkyl, C6-C24aryl,
C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, C7-C25aralkyl, CN, or
--CO--R28;R11 and R14 are independently of each other
hydrogen, halogen, C1-C18alkyl, C1-C18alkyl which is
substituted by E and/or interrupted by D, C1-C18
perfluoroalkyl, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, CN, or --CO--R28,R12, R13,
R15 and R16 are independently of each other H, halogen,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C1-C18 perfluoroalkyl,
C6-C24aryl, C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D,C7-C25aralkyl, CN or --CO--R28,X
is O, S, or NR17, wherein R17 is H; C6-C18aryl;
C2-C20heteroaryl; C6-C18aryl or
C2-C20heteroaryl which are substituted by
C1-C18alkyl, C1-C18 perfluoroalkyl, or
C1-C18alkoxy; C1-C18alkyl; or C1-C18alkyl
which is interrupted by --O--;or two substituents R1 and R2,
R4 and R6, R and R12 and/or R14 and R6, R2
and R3, R5 and R6, R12 and R13, and/or R15
and R16, which are adjacent to each other, together form a group
##STR00112## or two substituents R15 and R13, and/or R5
and R3, which are adjacent to each other, together form a group
##STR00113## wherein X3 is O, S, C(R119)(R120), or
NR17, R105, R106, R107, R108, R106' and
R108' are independently of each other H, C1-C18alkyl,
C1-C18alkyl which is substituted by E and/or interrupted by D,
C1-C18alkoxy, or C1-C18alkoxy which is substituted by
E and/or interrupted by D,R119 and R120 are independently of
each other C1-C18alkyl, C1-C18alkyl which is
substituted by E and/or interrupted by D, C6-C24aryl,
C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, or C7-C25aralkyl, orR119 and
R120 together form a group of formula ═CR121R122,
whereinR121 and R122 are independently of each other H,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C6-C24aryl, C6-C24aryl which
is substituted by G, or C2-C20heteroaryl, or
C2-C20heteroaryl which is substituted by G, orR119 and
R120 together form a five or six membered ring, which optionally can
be substituted by C1-C18alkyl, C1-C18alkyl which is
substituted by E and/or interrupted by D, C6-C24aryl,
C6-C14aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, C7-C25aralkyl, or
--C(═O)--R2, andR127 is H; C6-C18aryl;
C6-C18aryl which is substituted by C1-C18alkyl or
C1-C18alkoxy; C1-C18alkyl; or C1-C18alkyl
which is interrupted by --O--,D is --CO--; --COO--; --S--; --SO--;
--SO2--; --O--; --NR25--; --SiR30R31--;
--POR32--; --CR.sup.23.dbd.CR24--; or --C≡C--; andE is
--OR29; --SR29; --NR25R26; --COR28;
--COOR27; --CONR25R26; --CN; or halogen;G is E,
C1-C18alkyl, C1-C18alkyl which is interrupted by D,
C1-C18 perfluoroalkyl, C1-C18alkoxy, or
C1-C18alkoxy which is substituted by E and/or interrupted by
D,wherein R23, R24, R25 and R26 are independently of
each other H; C6-C18aryl; C6-C18aryl which is
substituted by C1-C18alkyl or C1-C18alkoxy;
C1-C18alkyl; or C1-C18alkyl which is interrupted by
--O--; orR25 and R26 together form a five or six membered ring,
R27 and R28 are independently of each other H;
C6-C18aryl; C6-C18aryl which is substituted by
C1-C18alkyl or C1-C18alkoxy; C1-C18alkyl;
or C1-C18alkyl which is interrupted by --O--,R29 is H;
C6-C18aryl; C6-C18aryl, which is substituted by
C1-C18alkyl or C1-C18alkoxy; C1-C18alkyl;
or C1-C18alkyl which is interrupted by --O--,R30 and
R31 are independently of each other C1-C18alkyl,
C6-C18aryl, or C6-C18aryl which is substituted by
C1-C18alkyl, andR32 is C1-C18alkyl,
C6-C18aryl, or C6-C18aryl which is substituted by
C1-C18alkyl.

3. The EL device according to claim 2, comprising a compound of the
formula X, or XI, wherein R and R4 are hydrogen,R2, R3,
R5 and R6 are independently of each other H,
C1-C18alkyl, C1-C18alkyl which is interrupted by D,
C1-C18 perfluoroalkyl, C1-C18alkoxy,
C1-C18alkoxy which is interrupted by D,
C7-C25aralkyl, or a group --X2--R18,R8 and
R9 are independently of each other H, C1-C18alkyl,
C1-C18alkyl which is interrupted by D, C1-C18
perfluoroalkyl, C1-C18alkoxy, C1-C18alkoxy which is
interrupted by D, or a group --X2--R18; or two substituents R
and R3 and/or R5 and R6, which are adjacent to each other,
together form a group ##STR00114## or two substituents R5 and
R3, which are adjacent to each other, together form a group
##STR00115## wherein R105, R106, R107 and --R108 are
independently of each other H, or C1-C8alkyl, orR8 and
R9 together form a group ##STR00116## wherein R205, R206,
R207, R208, R209 and R210 are independently of each
other H, C1-C18alkyl, C1-C18alkyl which is
substituted by E and/or interrupted by D, C1-C18alkoxy, or
C1-C18alkoxy which is substituted by E and/or interrupted by D,
C1-C18 perfluoroalkyl,R10 is H, C6-C18aryl,
which can be substituted by G, C2-C18heteroaryl, which can be
substituted by G, C1-C18alkyl, C1-C18alkyl which is
interrupted by D, C1-C18 perfluoroalkyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, or a group --X2--R18,wherein X2
is a C6-C12aryl, or C6-C12heteroaryl spacer, which
can be substituted one to two times with C1-C18alkyl,
C1-C18alkyl which is interrupted by D, C1-C18
perfluoroalkyl, C1-C18alkoxy, or C1-C18alkoxy which
is substituted by E and/or interrupted by D,and R18 is H,
C1-C18alkyl, C1-C18alkyl which is interrupted by D,
C1-C18 perfluoroalkyl, C1-C18alkoxy,
C1-C18alkoxy which is interrupted by D, or
--NR25R26;D is --CO--; --COO--; --S--; --SO--; --SO2--;
--O--; --NR25--; --CR.sup.23.dbd.CR24--; or --C≡C--;
whereinR23, R24, R25 and R26 are independently of
each other H; C6-C18aryl; C6-C18aryl which is
substituted by C1-C8alkyl or C1-C8alkoxy;
C1-C8alkyl; or C1-C8alkyl which is interrupted by
--O--, or R25 and R26 together form a five or six membered
ring.

4. The EL device according to claim 2, comprising a compound having the
formula ##STR00117## wherein R10 is H, C6-C18aryl which
can be substituted by G, C2-C18heteroaryl which can be
substituted by G, C1-C18alkyl, C1-C18alkyl which is
interrupted by D, C1-C18 perfluoroalkyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, or a group --X2--R18, wherein X2
is a C6-C12aryl or C6-C12heteroaryl spacer which can
be substituted one to two times with C1-C18alkyl,
C1-C18alkyl which is interrupted by D, C1-C18
perfluoroalkyl, C1-C18alkoxy, or C1-C18alkoxy which
is substituted by E and/or interrupted by D, and R18 is H,
C1-C18alkyl, C1-C18alkyl which is interrupted by D,
C1-C18 perfluoroalkyl, C1-C18alkoxy,
C1-C18alkoxy which is interrupted by D, or
--NR25R26--;R11 and R14 are hydrogen,R12,
R13, R15 and R16 are hydrogen,R17 is
C6-C18aryl; C6-C18aryl which is substituted by
C1-C18alkyl, C1-C18 perfluoroalkyl, or
C1-C18alkoxy; C1-C18alkyl; or C1-C18alkyl
which is interrupted by --O--; ortwo substituents R15 and R13,
R12 and R13 and/or R15 and R16, which are adjacent to
each other, together form a group ##STR00118## or two substituents
R15 and R13, which are adjacent to each other, together form a
group ##STR00119## wherein R105, R10, R107 and R108
are independently of each other H, or C1-C8alkyl,D is --S--;
--O--; or --NR25--;E is --OR29; --SR29;
--NR25R26; --CN; or F;G is E, C1-C18alkyl,
C1-C18alkyl which is interrupted by D, C1-C18
perfluoroalkyl, C1-C18alkoxy, or C1-C18alkoxy which
is substituted by E and/or interrupted by D, whereinR25 and R26
are independently of each other H; C6-C18aryl;
C6-C18aryl which is substituted by C1-C8alkyl or
C1-C8alkoxy; C1-C8alkyl; or C1-C8alkyl
which is interrupted by --O--, orR25 and R26 together form
##STR00120## R29 is C6-C18aryl; C6-C18aryl which
is substituted by C1-C18alkyl, or C1-C18alkoxy;
C1-C18alkyl; or C1-C18alkyl which is interrupted by
--O--.

5. The EL device according to claim 1, wherein A1, A2, A1'
and A2' are independently of each other ##STR00121## or A1 and
A1' or A2 and A2' together with the nitrogen atom to which
they are bonded form a heteroaromatic ring system ##STR00122## m' is 0,
1, or 2;m can be the same or different at each occurence and is 0, 1, 2,
or 3;R41 can be the same or different at each occurence and is Cl,
F, CN, N(R45)2, a C1-C25alkyl group, a
C4-C18cycloalkyl group, a C1-C25alkoxy group, in
which one or more carbon atoms which are not in neighbourhood to each
other could be replaced by --NR45--, --O--, --S--, or
--C(═O)--O--, and/or wherein one or more hydrogen atoms can be
replaced by F, a C6-C24aryl group, or a C6-C24aryloxy
group, wherein one or more carbon atoms can be replaced by O, S, or N,
and/or which can be substituted by one or more non-aromatic groups
R41, ortwo or more groups R41 form a ring system;R45 is H,
a C1-C25alkyl group, a C4-C18cycloalkyl group, in
which one or more carbon atoms which are not in neighbourhood to each
other could be replaced by --NR45''--, --O--, --S--,
--C(═O)--O--, or, --O--C(═O)--O--, and/or wherein one or more
hydrogen atoms can be replaced by F, a C6-C24aryl group, or a
C6-C24aryloxy group, wherein one or more carbon atoms can be
replaced by O, S, or N, and/or which can be substituted by one or more
non-aromatic groups R41, and R45'' is H, a
C1-C25alkyl group, or a C4-C18cycloalkyl
group,R116, R117 and R117' are independently of each other
H, halogen, --CN, C1-C18alkyl, C1-C18alkyl which is
substituted by E and/or interrupted by D, C6-C24aryl,
C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, C7-C25aralkyl, --C(═O)--R127,
--C(═O)OR127, or --C(═O)NR127R128, or substituents
R116, R117 and R117', which are adjacent to each other,
can form a ring,R119 and R120 are independently of each other
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C6-C24aryl, C6-C24aryl which
is substituted by G, C2-C20heteroaryl,
C2-C20heteroaryl which is substituted by G,
C2-C18alkenyl, C2-C18alkynyl, C1-C18alkoxy,
C1-C18alkoxy which is substituted by E and/or interrupted by D,
or C7-C25aralkyl, orR119 and R120 together form a
group of formula ═CR121R122, whereinR121 and R122
are independently of each other H, C1-C18alkyl,
C1-C18alkyl which is substituted by E and/or interrupted by D,
C6-C24aryl, C6-C24aryl which is substituted by G, or
C2-C20heteroaryl, or C2-C20heteroaryl which is
substituted by G, orR119 and R120 together form a five or six
membered ring, which optionally can be substituted by
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C6-C24aryl, C6-C24aryl which
is substituted by G, C2-C20heteroaryl,
C2-C20heteroaryl which is substituted by G,
C2-C18alkenyl, C2-C18alkynyl, C1-C18alkoxy,
C1-C18alkoxy which is substituted by E and/or interrupted by D,
C7-C25aralkyl, or --C(═O)--R127, andR126 and
R127 are independently of each other H; C6-C18aryl;
C6-C18aryl which is substituted by C1-C18alkyl or
C1-C18alkoxy; C1-C18alkyl; or C1-C18alkyl
which is interrupted by --O--,D is --CO--, --COO--, --S--, --SO--,
--SO2--, --O--, --NR65, --SiR70R71--, POR72--,
--CR.sup.63.dbd.CR64--, or --C≡C--, andE is --OR69,
SR69, --NR65R66, --COR68--COOR67,
--CONR65R66, --CN, or halogen,G is E, or
C1-C18alkyl,R63, R64, R65, R65 and R66
are independently of each other H; C6-C18aryl;
C6-C18aryl which is substituted by C1-C18alkyl or
C1-C18alkoxy; C1-C18alkyl; or C1-C18alkyl
which is interrupted by --O--; orR65 and R66 together form a
five or six membered ring,R67 and R68 are independently of each
other H; C6-C18aryl; C6-C18aryl which is substituted
by C1-C18alkyl, or C1-C18alkoxy;
C1-C18alkyl; or C1-C18alkyl which is interrupted by
--O--,R69 is H; C6-C18aryl; C6-C18aryl which is
substituted by C1-C18alkyl or C1-C18alkoxy;
C1-C18alkyl; or C1-C18alkyl which is interrupted by
--O--,R70 and R71 are independently of each other
C1-C18alkyl, C6-C18aryl, or C6-C18aryl
which is substituted by C1-C18alkyl, andR72 is
C1-C18alkyl, C6-C18aryl, or C6-C18aryl
which is substituted by C1-C18alkyl; orA1, A2,
A1' and A2' are independently of each other a group
##STR00123## wherein BU is ##STR00124## or

7. Electroluminescent device according to claim 1, comprising a cathode,
an anode, and therebetween a light emitting layer containing a host
material and a phosphorescent light-emitting material, wherein the host
material is a compound of formula I.

8. A compound of the formula ##STR00130## whereinA, Z1, Z2,
R1, R2, R3, R4, R5, R6, R7 and x are
as defined in claim 1, with the proviso that phenazine compounds
expressed by formula ##STR00131## are excluded, wherein each
R1-R4 is an H atom, a (substituted)alkyl group, aralkyl group,
aryl group, or heterocyclic group, wherein R1 and R2, and
R3 and R4 may form a 5-7 membered ring together with an N atom,
respectively; each R5-R7 is an H atom, (substituted)alkyl
group, alkoxy group, halogen atom or nitro group.

9. Solar cells, dye lasers or electroluminescent devices comprising a
compound of formula I according to claim 8.

10. A process for the preparation of compounds of the formula Ia or Ib
according to claim 12, wherein Z1 and Z2 are independently of
each other --NA1A1', or ##STR00132## m' is 0, 1, or 2; which
comprises reacting a compound of formula ##STR00133## wherein X10
stands for halogen, with a compound of formula HNA1A1', or
##STR00134## in the presence of a base and a catalyst in a solvent.

11. An electroluminescent (EL) device according to claim 1, comprising a
compound of the formula ##STR00135## wherein A is a 5-, 6-, or 7-membered
heteroaromatic ring, containing one nitrogen atom and at least one
further heteroatom selected from nitrogen, substituted nitrogen, oxygen
and sulfur,Ar and Ar' are independently of each other phenyl or naphthyl,
which may optionally be substituted by one or more groups selected from
C1-C25alkyl which may optionally be interrupted by --O-- or
C1-C25alkoxy,A1, A2, A1' and A2' are
independently of each other a C6-C24aryl group, a
C2-C30heteroaryl group, which can optionally be substituted, or
a group ##STR00136## wherein BU is ##STR00137## A3 and A3' are
independently of each other a C6-C24aryl group or a
C2-C30heteroaryl group, which can optionally be substituted,or
A1 and A1' or A2 and A2' or A3 and A3'
together with the nitrogen atom to which they are bonded form a
heteroaromatic ring system ##STR00138## m' is 0, 1, or 2;R41 can be
the same or different at each occurence and is Cl, F, CN,
NR45R45', a C1-C25alkyl group, a
C4-C18cycloalkyl group, a C1-C25alkoxy group, in
which one or more carbon atoms which are not in neighbourhood to each
other could be replaced by --NR45--, --O--, --S--, --C(═O)--O--,
or --O--C(═O)--O--, and/or wherein one or more hydrogen atoms can be
replaced by F, a C6-C21aryl group, or a C6-C24aryloxy
group, wherein one or more carbon atoms can be replaced by O, S, or N,
and/or which can be substituted by one or more non-aromatic groups
R41, or two or more groups R41 form a ring system;R45 and
R45' are independently of each other H, a C1-C25alkyl
group, a C4-C18cycloalkyl group, in which one or more carbon
atoms which are not in neighbourhood to each other could be replaced by
--NR45--, --O--, --S--, --C(═O)--O--, or, --O--C(═O)--O--,
and/or wherein one or more hydrogen atoms can be replaced by F, a
C6-C24aryl group, or a C6-C24aryloxy group, wherein
one or more carbon atoms can be replaced by O, S, or N, and/or which can
be substituted by one or more non-aromatic groups R41, andR45''
is H, a C1-C25alkyl group or a C4-C18cycloalkyl
group,m can be the same or different at each occurence and is 0, 1, 2, or
3.

12. A compound according to claim 8, of the formula ##STR00139## wherein A
is a 5-, 6-, or 7-membered heteroaromatic ring, containing one nitrogen
atom and at least one further heteroatom selected from nitrogen,
substituted nitrogen, oxygen and sulfur,Ar and Ar' are independently of
each other phenyl or naphthyl, which may optionally be substituted by one
or more groups selected from C1-C25alkyl which may optionally
be interrupted by --O-- or C1-C25alkoxy,A1, A2,
A1' and A2' are independently of each other a
C6-C24aryl group, a C2-C30heteroaryl group, which can
optionally be substituted, or a group ##STR00140## wherein BU is
##STR00141## A3 and A3' are independently of each other a
C6-C24aryl group or a C2-C30heteroaryl group, which
can optionally be substituted,or A' and A1' or A2 and A2'
or A3 and A3' together with the nitrogen atom to which they are
bonded form a heteroaromatic ring system ##STR00142## m' is 0, 1, or
2;R41 can be the same or different at each occurence and is Cl, F,
CN, NR45R45', a C1-C25alkyl group, a
C4-C18cycloalkyl group, a C1-C25alkoxy group, in
which one or more carbon atoms which are not in neighbourhood to each
other could be replaced by --NR45--, --O--, --S--, --C(═O)--O--,
or --O--C(═O)--O--, and/or wherein one or more hydrogen atoms can be
replaced by F, a C6-C24aryl group, or a C6-C24aryloxy
group, wherein one or more carbon atoms can be replaced by O, S, or N,
and/or which can be substituted by one or more non-aromatic groups
R41, or two or more groups R41 form a ring system;R45 and
R45' are independently of each other H, a C1-C25alkyl
group, a C4-C18cycloalkyl group, in which one or more carbon
atoms which are not in neighbourhood to each other could be replaced by
--NR45''--, --O--, --S--, --C(═O)--O--, or, --O--C(═O)--O--,
and/or wherein one or more hydrogen atoms can be replaced by F, a
C6-C24aryl group, or a C6-C24aryloxy group, wherein
one or more carbon atoms can be replaced by O, S, or N, and/or which can
be substituted by one or more non-aromatic groups R41, andR45''
is H, a C1-C25alkyl group or a C4-C18cycloalkyl
group,m can be the same or different at each occurence and is 0, 1, 2, or
3.

Description:

especially as host for phosphorescent compounds. The hosts may function
with phosphorescent materials to provide improved efficiency, stability,
manufacturability, or spectral characteristics of electroluminescent
devices.

[0002]JP9013025 relates to an electroluminescent element a quinoxaline
derivative represented by the formula

##STR00002##

wherein X is a C2-C5alkyl or the like; and R1 to R8,
which are independent of each other, are each H, a halogen, a
C1-C6alkyl or the like.

which are used as a component material of an organic EL element. In the
formula, R1 to R12 each independently represent an hydrogen
atom, a halogen atom, a hydroxyl group, a substituted or unsubstituted
amino group, a nitro group, a cyano group, a substituted or unsubstituted
alkyl group, a substituted or unsubstituted alkenyl group, a substituted
or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxy
group, a substituted or unsubstituted aromatic hydrocarbon group, a
substituted or unsubstituted aromatic heterocycle group, a substituted or
unsubstituted aralkyl group, a substituted or unsubstituted aryloxy
group, a substituted or unsubstituted alkoxycarbonyl group, or a carboxyl
group. R1 to R12 may form two rings out of them.

[0005]JP2134644 relates to an electrophotographic sensitive body having a
phenazine compound in a photosensitive layer. The phenazine compound is
expressed by formula

##STR00005##

wherein each R1-R4 is an H atom, a (substituted)alkyl group,
aralkyl group, aryl group, or heterocyclic group, wherein R1 and
R2, and R3 and R4 may form a 5-7 membered ring together
with an N atom, respectively; each R5-R7 is an H atom,
(substituted)alkyl group, alkoxy group, halogen atom or nitro group.

[0006]US20060289882 relates to an organic electroluminescent device,
wherein the electron extracting layer may be formed of a
hexaazatriphenylene derivative represented by the following structural
formula

##STR00006##

wherein R represents hydrogen, an alkyl group having a carbon number of 1
to 10, an alkyloxy group having a carbon number of 1 to 10, a
dialkylamine group having a carbon number of 1 to 10, F, Cl, Br, I or CN.

[0007]US20070029927 discloses aromatic amine derivative represented by the
following general formula (1):

##STR00007##

wherein Ar1 to Ar4 each independently represents a substituted
or unsubstituted aryl group having 6 to 30 ring carbon atoms or a
substituted or unsubstituted heteroaryl group having 5 to 30 ring carbon
atoms;L1 and L2 each independently represents a single bond, a
substituted or unsubstituted arylene group having 6 to 30 ring carbon
atoms or a substituted or unsubstituted heteroarylene group having 5 to
30 ring carbon atoms;when both L1 and L2 are single bonds,
however, a case where both Ar1 and Ar3 each represents a
substituted or unsubstituted phenyl group and further, where both
Ar2 and Ar4 each represents a substituted or unsubstituted
biphenylyl group or a substituted or unsubstituted phenyl group is
excluded; R represents a substituent and when R exists two or more, they
may bond each other to form a ring; and n represents an integer of 0 to 8
and their use in organic electroluminescence devices.

[0008]JP2134644 relates to phenazine compounds of formula

##STR00008##

wherein each of R1-R4 is an H atom, a (substituted)alkyl group,
aralkyl group, aryl group, or heterocyclic group, wherein R1 and
R2, and R3 and R4 may form a 5-7 membered ring together
with an N atom, respectively; each of R5-R7 is an H atom,
(substituted)alkyl group, alkoxy group, halogen atom or nitro group. When
the phenazine compounds are incorporated into a photosensitive layer of
an electrophotographic sensitive body.

[0009]JP2000323278 relates to an emitter including an organic phosphor
having an imidazole structure of the formula

##STR00009##

wherein R1 may be either same or different respectively and selected
from hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an
alkenyl group, a cycloalkenyl group, etc., X1 is a bonding unit and
selected from a substituted or non-substituted aromatic ring,
heterocycle, a saturated fat chain, etc., Y1 is selected from a
single bond or a combination of either of single bond, an alkyl chain, an
alkylene chain, an ether chain, etc., and Ar is selected from a
substituted or non-substituted aromatic ring, heterocycle, etc. and z
expresses a natural number. The organic phosphor is preferably a light
emitting material having a guest material doped in a host material.

[0010]JP 2001023777 describes compounds of the formula

##STR00010##

wherein R1 to R9 represent bonding, hydrogen, an alkyl group, a
cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl
group, an alkoxy group, an alkylthio group, an arylether group, an aryl
thioether group, an aryl group, a heterocyclic group, halogen, a cyano
group, an aldehyde group, a carbonyl group, an ester group, a carbamoyl
group, an amino group, a nitro group, a silyl group, a siloxyanyl group,
and ring structure formed between adjacent substituting groups, and
Z1 represents oxygen, sulfur, nitrogen, or saturated hydrocarbon.
The compounds having a phenanthroazole skeleton are suitable as a host
material or a dopant material in a material of a hole transport layer, an
electron transport layer, and a luminescent layer. No compounds, wherein
any of R1 to R9 is an aryl substituted amino group are
disclosed.

[0011]JP2001118683 relates to a luminescent element, wherein the
luminescent material is at least composed of a guest material and a host
material and the peak of the emission spectrum of the host material is
more than 300 nm and less than 460 nm. The following phenanthroazole
compound is explicitly disclosed:

##STR00011##

[0012]JP2002050473 describes an element, in which a light emitting
substance exists between a positive electrode and a negative electrode
and which emits light by electric energy, and the element contains at
least one kind of product formed by a photoreaction. The following
phenanthroazole compound is explicitly disclosed:

##STR00012##

[0013]JP2003059670 describes a light-emitting element having a structure
in which at least a positive electrode, a luminous layer, an electron
carrier layer, and a negative electrode are laminated in order, the
electron carrier layer has an ionization potential 0.1 eV or more larger
than the ionization potential of the luminous layer, and the material
that mainly constitutes the luminous layer and the electron carrier layer
is made of an organic compound having sublimation performance, and
further, the organic compound that mainly constitutes the electron
carrier layer has a molecular weight of 400 or more and a glass
transition temperature of 90° C. or more. The following
phenanthroazole compound is explicitly disclosed:

##STR00013##

[0014]JP2002367786 describes a luminous element having a sequentially
laminated structure of at least a positive electrode, a luminous layer, a
hole transport layer, an electron transport layer and a negative
electrode, the relation between the luminous layer and the electron
transport layer is (Ip(ETL)-Ip(EML))>(Ea(ETL)-Ea(EML)). The main
material composing the luminous layer and the electron transport layer is
made of an organic compound with sublimatic nature, and the main material
composing the electron transport layer is an organic compound with
molecular mass of not less than 400. [Ea: electron affinity (eV), Ip:
ionization potential (eV), EML: luminous layer, and ETL: electron
transport layer]. The following phenanthroazole compound is explicitly
disclosed:

##STR00014##

[0015]Notwithstanding these developments, there remains a need for EL
devices comprising new host materials, and especially hosts that will
function with phosphorescent materials to provide improved efficiency,
stability, manufacturability, or spectral characteristics of
electroluminescent devices.

[0016]Accordingly, the present invention provides an EL device, comprising
a compound of the formula

##STR00015##

wherein A is a 5-, 6-, or 7-membered heteroaromatic ring, containing at
least one heteroatom selected from nitrogen, oxygen and sulfur,
especially one nitrogen atom and at least one further heteroatom selected
from nitrogen, substituted nitrogen, oxygen and sulfur,

Z1 is

##STR00016##

[0017]--NA1A1', --P(═O)A4A4', or
--SiA6A7A8,

Z2 is

##STR00017##

[0018]--NA2A2', 2-P(═O)A5A5', or
--SiA6'A7'A8',

[0019]Ar and Ar' are independently of each other C6-C14aryl,
such as phenyl, or naphthyl, which may optionally be substituted by one
or more groups selected from C1-C25alkyl, which may optionally
be interrupted by --O--, or C1-C25alkoxy,R1, R2,
R3, R4, R5 and R6 are independently of each other
hydrogen, halogen, or an organic substituent, orR1 and R2,
R4 and R6, R2 and R3, R5 and R3 and/or
R5 and R6, which are adjacent to each other, together form an
aromatic, or heteroaromatic ring, or ring system, which can optionally be
substituted,R7 is an organic substituent, wherein two or more
substituents R7 in the same molecule may have different meanings, or
can form together an aromatic, or heteroaromatic ring, or ring system,
andx is 0, or an integer of 1 to 5;A1, A2, A1 and A2'
are independently of each other a C6-C24aryl group, a
C2-C30heteroaryl group, which can optionally be substituted, or
a group

##STR00018##

wherein BU is a bridging unit, such as

##STR00019##

A3 and A3' are independently of each other a
C6-C24aryl group, or a C2-C30heteroaryl group, which
can optionally be substituted, or A1 and A1' or A2 and
A2' or A3 and A3' together with the nitrogen atom to which
they are bonded form a heteroaromatic ring, or ring system, such as

##STR00020##

m' is 0, 1, or 2;A4, A4', A6, A7, A8, A2,
A2', A5, A5', A6', A7', and A8' are
independently of each other a C6-C24aryl group, or a
C2-C30heteroaryl group, which can optionally be
substituted,R41 can be the same or different at each occurence and
is Cl, F, CN, NR45R45', a C1-C25alkyl group, a
C4-C18cycloalkyl group, a C1-C25alkoxy group, in
which one or more carbon atoms which are not in neighbourhood to each
other could be replaced by --NR45--, --O--, --S--, --C(═O)--O--,
or --O--C(═O)--O--, and/or wherein one or more hydrogen atoms can be
replaced by F, a C6-C24aryl group, or a C6-C24aryloxy
group, wherein one or more carbon atoms can be replaced by O, S, or N,
and/or which can be substituted by one or more non-aromatic groups
R41, or two or more groups R41 form a ring system;R45 and
R45' are independently of each other H, a C1-C25alkyl
group, a C4-C18cycloalkyl group, in which one or more carbon
atoms which are not in neighbourhood to each other could be replaced by
--NR45''--, --O--, --S--, --C(═O)--O--, or, --O--C(═O)--O--,
and/or wherein one or more hydrogen atoms can be replaced by F, a
C6-C24aryl group, or a C6-C24aryloxy group, wherein
one or more carbon atoms can be replaced by O, S, or N, and/or which can
be substituted by one or more non-aromatic groups R41, andR45''
is H, a C1-C25alkyl group, or a C4-C18cycloalkyl
group,m can be the same or different at each occurence and is 0, 1, 2, or
3, especially 0, 1, or 2, very especially 0 or 1.

[0020]In addition, the present invention relates to compounds of the
formula

are excluded, wherein each R1-R4 is an H atom, a
(substituted)alkyl group, aralkyl group, aryl group, or heterocyclic
group, wherein R1 and R2, and R3 and R4 may form a
5-7 membered ring together with an N atom, respectively; each
R5-R7 is an H atom, (substituted)alkyl group, alkoxy group,
halogen atom or nitro group.

[0021]The compounds of formula I can be used in organic light emitting
diodes (OLEDs), especially as hosts for phosphorescent compounds.
Accordingly, the present invention also provides an electroluminescent
device comprising a cathode, an anode, and therebetween a light emitting
layer containing a host material and a phosphorescent light-emitting
material wherein the host material is a compound of formula I.

[0022]Examples of Z1 and Z2 are

##STR00023##

wherein R200 is C1-C25alkyl, which may optionally be
interrupted by --O--, or C1-C25alkoxy;

##STR00024##

wherein R116 and R117 are as defined below. Z1 is
preferably a group

##STR00025##

or --NA1A1'. Z2 is preferably a group

##STR00026##

or --NA2A2'. Z1 and Z2 may be different, but are
preferably the same.

[0023]A is a 5-, 6-, or 7-membered heteroaromatic ring, containing one
heteroatom selected from nitrogen, oxygen and sulphur, which can be
substituted and/or can be part of a fused aromatic or heteroaromatic ring
system. Non-limiting examples of A are:

##STR00027##

wherein R7 has the meaning of R8, R8'' has the meaning of
R8, X is O, S, N--R17, wherein R205, R206R207,
R208R209, R210, R8, R9, R8', R9',
R10 and R17 are as defined below, p is 0, 1, 2, or 3 and the
dotted line - - - indicates the bonding to the benzene ring.

[0024]Preferably, the compound of formula I is a compound according of
formula:

##STR00028## ##STR00029##

R1 and R4 are independently of each other hydrogen, halogen,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C1-C18 perfluoroalkyl,
C2-C18alkenyl, C2-C18alkynyl, C1-C18alkoxy,
C1-C18alkoxy which is substituted by E and/or interrupted by D,
CN, or --CO--R28, R2, R3, R5 and R6 are
independently of each other H, halogen, C1-C18alkyl,
C1-C18alkyl which is substituted by E and/or interrupted by D,
C1-C18 perfluoroalkyl, C6-C24aryl,
C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, C7-C25aralkyl, CN, or
--CO--R28,R8 and R9 are independently of each other H,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C1-C18 perfluoroalkyl,
C6-C24aryl, C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, C7-C25aralkyl, CN, or --CO--R28,
orR8 and R9 together form a group

##STR00030##

wherein R206', R208', R205, R206, R207,
R208, R209 and R210 are independently of each other H,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C1-C18alkoxy, or
C1-C18alkoxy which is substituted by E and/or interrupted by D,
C1-C18 perfluoroalkyl, C6-C24aryl,
C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C7-C25aralkyl, CN, or --CO--R28,R10 is H,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C1-C18 perfluoroalkyl,
C6-C24aryl, C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, C7-C25aralkyl, or --CO--R28,
R8' and R9' are independently of each other H, CN,
--COOR27; --CONR25R26, C1-C18alkyl,
C1-C18alkyl which is substituted by E and/or interrupted by D,
C1-C18 perfluoroalkyl, C6-C24aryl,
C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, C7-C25aralkyl, CN, or
--CO--R28;R11 and R14 are independently of each other
hydrogen, halogen, C1-C18alkyl, C1-C18alkyl which is
substituted by E and/or interrupted by D, C1-C18
perfluoroalkyl, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, CN, or --CO--R28,R12, R13,
R15 and R16 are independently of each other H, halogen,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C1-C18 perfluoroalkyl,
C6-C24aryl, C6-C24aryl which is substituted by G,
C2-C20heteroaryl, C2-C20heteroaryl which is
substituted by G, C2-C18alkenyl, C2-C18alkynyl,
C1-C18alkoxy, C1-C18alkoxy which is substituted by E
and/or interrupted by D, C7-C25aralkyl, CN or --CO--R28,X
is O, S, or NR17, wherein R17 is H; C6-C18aryl;
C2-C20heteroaryl; C6-C18aryl, or
C2-C20heteroaryl, which are substituted by
C1-C18alkyl, C1-C18 perfluoroalkyl, or
C1-C18alkoxy; C1-C18alkyl; or C1-C18alkyl
which is interrupted by --O--;or two substituents R1 and R2,
R4 and R6, R11 and R12, and/or R14 and R16,
R2 and R3, R5 and R6, R12 and R13, and/or
R15 and R16, which are adjacent to each other, together form a
group

##STR00031##

or two substituents R15 and R13, and/or R5 and R3,
which are adjacent to each other, together form a group

##STR00032##

wherein X3 is O, S, C(R119)(R120), or NR17, wherein
R17 is as defined above, R105, R106, R107, R108,
R106' and R108' are independently of each other H,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C1-C18alkoxy, or
C1-C18alkoxy which is substituted by E and/or interrupted by
D,R119 and R120 are independently of each other
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C6-C24aryl, C6-C24aryl which
is substituted by G, C2-C20heteroaryl,
C2-C20heteroaryl which is substituted by G,
C2-C18alkenyl, C2-C18alkynyl, C1-C18alkoxy,
C1-C18alkoxy which is substituted by E and/or interrupted by D,
or C7-C25aralkyl, orR119 and R120 together form a
group of formula ═CR121R122, whereinR121 and R122
are independently of each other H, C1-C18alkyl,
C1-C18alkyl which is substituted by E and/or interrupted by D,
C6-C24aryl, C6-C24aryl which is substituted by G, or
C2-C20heteroaryl, or C2-C20heteroaryl which is
substituted by G, orR119 and R120 together form a five or six
membered ring, which optionally can be substituted by
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C6-C24aryl, C6-C24aryl which
is substituted by G, C2-C20heteroaryl,
C2-C20heteroaryl which is substituted by G,
C2-C18alkenyl, C2-C18alkynyl, C1-C18alkoxy,
C1-C18alkoxy which is substituted by E and/or interrupted by D,
C7-C25aralkyl, or --C(═O)--R127, andR127 is H;
C6-C18aryl; C6-C18aryl which is substituted by
C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl;
or C1-C18alkyl which is interrupted by --O--,D is --CO--;
--COO--; --S--; --SO--; --SO2--; --O--; --NR25--; --Si
R30R31--; --POR32; --CR23═CR24; or
--C≡C--; andE is --OR29; --SR29; --NR25R26;
--COR28; --COOR27; --CONR25R26; --CN; or halogen; G
is E, C1-C18alkyl, C1-C18alkyl which is interrupted
by D, C1-C18 perfluoroalkyl, C1-C18alkoxy, or
C1-C18alkoxy which is substituted by E and/or interrupted by D,
whereinR23, R24, R25 and R26 are independently of
each other H; C6-C18aryl; C6-C18aryl which is
substituted by C1-C18alkyl, or C1-C18alkoxy;
C1-C18alkyl; or C1-C18alkyl which is interrupted by
--O--; orR25 and R26 together form a five or six membered ring,
R27 and R23 are independently of each other H;
C6-C18aryl; C6-C18aryl which is substituted by
C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl;
or C1-C18alkyl which is interrupted by --O--,R29 is H;
C6-C18aryl; C6-C18aryl, which is substituted by
C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl;
or C1-C18alkyl which is interrupted by --O--,R30 and
R31 are independently of each other C1-C18alkyl,
C6-C18aryl, or C6-C18aryl, which is substituted by
C1-C18alkyl, andR32 is C1-C18alkyl,
C6-C18aryl, or C6-C18aryl, which is substituted by
C1-C18alkyl, andA1, A2, A1 and A2' are as
defined above.

[0025]Preferably, R116 and R117 are independently of each other
H, C1-C12alkyl, such as methyl, ethyl, n-propyl, iso-propyl,
n-butyl, isobutyl, sec-butyl, t-butyl, 2-methylbutyl, n-pentyl,
isopentyl, n-hexyl, 2-ethylhexyl, or n-heptyl, C1-C12alkyl
which is substituted by E and/or interrupted by D, such as
--CH2OCH3, --CH2OCH2CH3,
--CH2OCH2CH2OCH3, or
--CH2OCH2CH2OCH2CH3, C6-C14aryl, such
as phenyl, naphthyl, or biphenylyl, C5-C12cycloalkyl, such as
cyclohexyl, C6-C14aryl which is substituted by G, such as
--C6H4OCH3, --C6H4OCH2CH3,
--C6H3(OCH3)2, or
--C6H3(OCH2CH3)2, --C6H4--CH3,
--C6H3(CH3)2, --C6H2(CH3)3, or
--C6H4tBu.

[0026]X is O, S, or NR17. In case of compounds of formula XII and
XVIII X is preferably O, or NR17. In case of compounds of formula
XIII and XIX X is preferably S, or NR17.

[0027]R25 and R26 together form a five or six membered ring, in
particular

##STR00033##

R29 is C6-C18aryl; C6-C18aryl, which is
substituted by C1-C18alkyl, or C1-C18alkoxy;
C1-C18alkyl; or C1-C18alkyl which is interrupted by
--O--.

[0028]In a preferred embodiment the present invention is directed to an EL
device comprising compounds of formula

[0030]A1, A2, A1' and A2' are independently of each
other especially phenyl, naphthyl, anthryl, biphenylyl, 2-fluorenyl,
phenanthryl, or perylenyl, which can optionally be substituted, such as
R17 is preferably H, C1-C12alkyl, such as methyl, ethyl,
n-propyl, iso-propyl, n-butyl, isobutyl, sec-butyl, t-butyl,
2-methylbutyl, n-pentyl, isopentyl, n-hexyl, 2-ethylhexyl, n-heptyl, or
C6-C14aryl, such as phenyl, naphthyl, or biphenylyl.

[0031]Preferably, R119 and R120 are independently of each other
C1-C12alkyl, such as methyl, ethyl, n-propyl, iso-propyl,
n-butyl, sec-butyl, hexyl, octyl, or 2-ethyl-hexyl, C1-C12alkyl
which is substituted by E and/or interrupted by D, such as
--CH2(OCH2CH2)wOCH3, w=1, 2, 3, or 4,
C6-C14aryl, such as phenyl, naphthyl, or biphenylyl,
C6-C14aryl which is substituted by G, such as
--C6H4OCH3, --C6H4OCH2CH3,
--C6H3(OCH3)2,
--C6H3(OCH2CH3)2, --C6H4--CH3,
--C6H3(CH3)2, --C6H2(CH3)3, or
--C6H4tBu, or R119 and R120 together form a 4 to 8
membered ring, especially a 5 or 6 membered ring, such as cyclohexyl, or
cyclopentyl, which can optionally be substituted by C1-C8alkyl.

[0033]E is preferably --OR29; --SR29; --NR25R25;
--COR28; --COOR27; --CONR25R25; or --CN; wherein
R25, R27, R23 and R29 are independently of each other
C1-C12alkyl, such as methyl, ethyl, n-propyl, iso-propyl,
n-butyl, isobutyl, sec-butyl, hexyl, octyl, or 2-ethyl-hexyl, or
C6-C14aryl, such as phenyl, naphthyl, or biphenylyl, which may
optionally be substituted.

[0034]G has the same preferences as E, or is C1-C18alkyl,
especially C1-C12alkyl, such as methyl, ethyl, n-propyl,
iso-propyl, n-butyl, isobutyl, sec-butyl, hexyl, octyl, or 2-ethyl-hexyl.

[0035]Compounds of the formula X, XI and XII are preferred.

[0036]Compounds of the formula X, or XII are even more preferred, wherein
R1 and R4 are hydrogen,

R2, R3R5 and R6 are independently of each other H,
C1-C18alkyl, C1-C18alkyl which is interrupted by D,
C1-C18 perfluoroalkyl, C1-C18alkoxy,
C1-C18alkoxy which is interrupted by D,
C7-C25aralkyl, or a group --X2--R13,R8 and
R9 are independently of each other H, C1-C18alkyl,
C1-C18alkyl which is interrupted by D, C1-C18
perfluoroalkyl, C6-C18aryl, which may optionally be substituted
by C1-C18alkyl, C1-8alkoxy, or C1-C18alkoxy
which is interrupted by D; C1-C18alkoxy, C1-C18alkoxy
which is interrupted by D, or a group --X2--R13; ortwo
substituents R2 and R3 and/or R5 and R6, which are
adjacent to each other, together form a group

##STR00036##

or two substituents R5 and R3, which are adjacent to each other,
together form a group

##STR00037##

wherein R105, R106, R107 and --R108 are independently
of each other H, or C1-C8alkyl, orR8 and R9 together
form a group

##STR00038##

wherein R205, R206, R207, R20, R209 and R210
are independently of each other H, C1-C18alkyl,
C1-C18alkyl which is substituted by E and/or interrupted by D,
C1-C18alkoxy, or C1-C18alkoxy which is substituted by
E and/or interrupted by D, C1-C18 perfluoroalkyl,R10 is H,
C6-C18aryl, which can be substituted by G,
C2-C18heteroaryl, which can be substituted by G,
C1-C18alkyl, C1-C18alkyl which is interrupted by D,
C1-C18 perfluoroalkyl, C1-C18alkoxy,
C1-C18alkoxy which is substituted by E and/or interrupted by D,
or a group --X2--R18, wherein X2 is a spacer, such as
C6-C12aryl, or C6-C12heteroaryl, especially phenyl,
or naphthyl, which can be substituted one more, especially one to two
times with C1-C18alkyl, C1-C18alkyl which is
interrupted by D, C1-C18 perfluoroalkyl,
C1-C18alkoxy, or C1-C18alkoxy which is substituted by
E and/or interrupted by D, and R13 is H, C1-C18alkyl,
C1-C18alkyl which is interrupted by D, C1-C18
perfluoroalkyl, C1-C18alkoxy, C1-C18alkoxy which is
interrupted by D, or --NR25R26;D is --CO--; --COO--; --S--;
--SO--; --SO2--; --O--; --NR25--; --CR23═CR24--;
or --C≡C--; whereinR23, R24, R25 and R26 are
independently of each other H; C6-C18aryl; C6-C18aryl
which is substituted by C1-C8alkyl, or C1-C8alkoxy;
C1-C8alkyl; or C1-C8alkyl which is interrupted by
--O--, or R25 and R26 together form a five or six membered
ring.

[0037]In a further preferred embodiment the present invention relates to
compounds of formula

##STR00039##

wherein R10 is H, C6-C18aryl, which can be substituted by
G, C2-C18heteroaryl, which can be substituted by G,
C1-C18alkyl, C1-C18alkyl which is interrupted by D,
C1-C18 perfluoroalkyl, C1-C18alkoxy,
C1-C18alkoxy which is substituted by E and/or interrupted by D,
or a group --X2--R18, wherein X2 is a spacer, such as
C6-C12aryl, or C6-C12heteroaryl, especially phenyl,
or naphthyl, which can be substituted one more, especially one to two
times with C1-C18alkyl, C1-C18alkyl which is
interrupted by D, C1-C18 perfluoroalkyl,
C1-C18alkoxy, or C1-C18alkoxy which is substituted by
E and/or interrupted by D, and R13 is H, C1-C18alkyl,
C1-C18alkyl which is interrupted by D, C1-C18
perfluoroalkyl, C1-C18alkoxy, C1-C18alkoxy which is
interrupted by D, or --NR25R26--;R11 and R14 are
hydrogen,R12, R13R15 and R16 are hydrogen,R17 is
C6-C18aryl; C6-C18aryl which is substituted by
C1-C18alkyl, C1-C18 perfluoroalkyl, or
C1-C18alkoxy; C1-C18alkyl; or C1-C18alkyl
which is interrupted by --O--; ortwo substituents R5 and R3,
R12 and R13 and/or R15 and R16, which are adjacent to
each other, together form a group

##STR00040##

or two substituents R15 and R13, which are adjacent to each
other, together form a group

##STR00041##

wherein R105, R106, R107 and R108 are independently of
each other H, or C1-C8alkyl,

D is --S--; --O--; or --NR25--;

[0038]E is --OR29; --SR29; --NR25R26; --CN; or F; G is
E, C1-C18alkyl, C1-C18alkyl which is interrupted by
D, C1-C18 perfluoroalkyl, C1-C18alkoxy, or
C1-C18alkoxy which is substituted by E and/or interrupted by D,
whereinR25 and R26 are independently of each other H;
C6-C18aryl; C6-C18aryl which is substituted by
C1-C8alkyl, or C1-C8alkoxy; C1-C8alkyl; or
C1-C8alkyl which is interrupted by --O--, or

##STR00042##

or A1 and A1' or A2 and A2' together with the nitrogen
atom to which they are bonded form a heteroaromatic ring, or ring system,
such as

##STR00043##

m' is 0, 1, or 2;m can be the same or different at each occurence and is
0, 1, 2, or 3, especially 0, 1, or 2, very especially 0 or 1;R41 can
be the same or different at each occurence and is Cl, F, CN,
N(R45)2, a C1-C25alkyl group, a
C4-C18cycloalkyl group, a C1-C25alkoxy group, in
which one or more carbon atoms which are not in neighbourhood to each
other could be replaced by --NR45--, --O--, --S--, or
--C(═O)--O--, and/or wherein one or more hydrogen atoms can be
replaced by F, a C6-C24aryl group, or a C6-C24aryloxy
group, wherein one or more carbon atoms can be replaced by O, S, or N,
and/or which can be substituted by one or more non-aromatic groups
R41, or two or more groups R41 form a ring system;R45 is
H, a C1-C25alkyl group, a C4-C18cycloalkyl group, in
which one or more carbon atoms which are not in neighbourhood to each
other could be replaced by --NR45''--, --O--, --S--,
--C(═O)--O--, or, --O--C(═O)--O--, and/or wherein one or more
hydrogen atoms can be replaced by F, a C6-C24aryl group, or a
C6-C24aryloxy group, wherein one or more carbon atoms can be
replaced by O, S, or N, and/or which can be substituted by one or more
non-aromatic groups R41, andR45'' is H, a C1-C25alkyl
group, or a C4-C18cycloalkyl group,R116, R117 and
R117 are independently of each other H, halogen, --CN,
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C6-C24aryl, C6-C24aryl which
is substituted by G, C2-C20heteroaryl,
C2-C20heteroaryl which is substituted by G,
C2-C18alkenyl, C2-C18alkynyl, C1-C18alkoxy,
C1-C18alkoxy which is substituted by E and/or interrupted by D,
C7-C25aralkyl, --C(═O)--R127, --C(═O)OR127,
or --C(═O)NR127R126, orsubstituents R116, R117
and R117', which are adjacent to each other, can form a
ring,R119 and R120 are independently of each other
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C6-C24aryl, C6-C24aryl which
is substituted by G, C2-C20heteroaryl,
C2-C20heteroaryl which is substituted by G,
C2-C18alkenyl, C2-C18alkynyl, C1-C18alkoxy,
C1-C18alkoxy which is substituted by E and/or interrupted by D,
or C7-C25aralkyl, orR119 and R120 together form a
group of formula ═CR121R122, whereinR121 and R122
are independently of each other H, C1-C18alkyl,
C1-C18alkyl which is substituted by E and/or interrupted by D,
C6-C24aryl, C6-C24aryl which is substituted by G, or
C2-C20heteroaryl, or C2-C20heteroaryl which is
substituted by G, orR119 and R120 together form a five or six
membered ring, which optionally can be substituted by
C1-C18alkyl, C1-C18alkyl which is substituted by E
and/or interrupted by D, C6-C24aryl, C6-C24aryl which
is substituted by G, C2-C20heteroaryl,
C2-C20heteroaryl which is substituted by G,
C2-C18alkenyl, C2-C18alkynyl, C1-C18alkoxy,
C1-C18alkoxy which is substituted by E and/or interrupted by D,
C7-C25aralkyl, or --C(═O)--R127, andR126 and
R127 are independently of each other H; C6-C18aryl;
C6-C18aryl which is substituted by C1-C18alkyl, or
C1-C18alkoxy; C1-C18alkyl; or C1-C18alkyl
which is interrupted by --O--,D is --CO--, --COO--, --S--, --SO--,
--SO2--, --O--, --NR65--, --SiR70R71--,
--POR72--CR63═CR64, or --C≡C--, andE is
--OR69, --SR69, --NR65R66, --COR68,
--COOR67--CONR65R66--CN, or halogen,G is E, or
C1-C18alkyl,R63, R64, R65 and R66 are
independently of each other H; C6-C18aryl; C6-C18aryl
which is substituted by C1-C18alkyl, C1-C18alkoxy;
C1-C18alkyl; or C1-C18alkyl which is interrupted by
--O--; orR65 and R66 together form a five or six membered
ring,R67 and R63 are independently of each other H;
C6-C18aryl; C6-C18aryl which is substituted by
C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl;
or C1-C18alkyl which is interrupted by --O--,R69 is H;
C6-C18aryl; C6-C18aryl, which is substituted by
C1-C18alkyl, C1-C18alkoxy; C1-C18alkyl; or
C1-C18alkyl which is interrupted by --O--,R70 and R71
are independently of each other C1-C18alkyl,
C6-C18aryl, or C6-C18aryl, which is substituted by
C1-C18alkyl, andR72 is C1-C18alkyl,
C6-C18aryl, or C6-C18aryl, which is substituted by
C1-C18alkyl; orA1, A2, A1' and A2' are
independently of each other a group

##STR00044##

wherein BU is

##STR00045##

wherein R41 and m are as defined above.

[0039]Examples of

##STR00046##

[0040]Examples of groups

##STR00047##

are shown below:

##STR00048##

wherein R41, R116, R117, R119, R120 and m are as
defined above.

[0041]Compounds of the formula

##STR00049##

are preferred, wherein R8 and R9 are independently of each other

##STR00050##

R17 is R8, or a group

##STR00051##

R10 is R8, or a group

##STR00052##

[0042]R17' is R17, or a group

##STR00053##

wherein n1 is 0, or an integer 1, 2, 3, or 4, n2 is 0, or an
integer 1, 2, or 3, n3 is 0, or an integer 1, 2, 3, 4, or
5,R101, R102 and R103 are independently of each other
C1-C25alkyl, which may optionally be interrupted by --O--, or
C1-C25alkoxy;Z1 and Z2 are as defined above and are
preferably independently of each other

##STR00054##

very especially a group of formula

##STR00055##

m' is 0, 1, or 2, --NA1A1', or a group

##STR00056##

wherein A1, A1', A3 and A3' are independently of each
other

##STR00057##

R116 and R117 are independently of each other
C1-C25alkyl, which may optionally be interrupted by --O--, or
C1-C25alkoxy;

Bu is

##STR00058##

[0043]wherein R41 can be the same or different at each occurence and
is C1-C25alkyl, which may optionally be interrupted by --O--,
or C1-C25alkoxy; n is 0, 1, or 2.

[0044]In another embodiment of the present invention EL devices are
preferred, comprising compounds of formula

##STR00059##

wherein Z1 and Z2 are as defined above.

[0045]Examples of particularly preferred compounds are shown below:

##STR00060## ##STR00061## ##STR00062## ##STR00063## ##STR00064##

[0046]The compounds of the formula I, wherein Z1 and Z2 are
independently of each other --NA1A1', or

##STR00065##

can, for example, be prepared according to a process, which comprises
reacting a compound of formula

##STR00066##

wherein X10 stands for halogen, such as bromo or iodo, preferably
iodo, with a compound of formula HNA1A1', or

[0055]C1-C18 perfluoroalkyl, especially C1-C4
perfluoroalkyl, is a branched or unbranched radical such as for example
--CF3, --CF2CF3, --CF2CF2CF3,
--CF(CF3)2, --(CF2)3CF3, and
--C(CF3)3.

[0056]The terms "haloalkyl, haloalkenyl and haloalkynyl" mean groups given
by partially or wholly substituting the above-mentioned alkyl group,
alkenyl group and alkynyl group with halogen, such as trifluoromethyl
etc. The "aldehyde group, ketone group, ester group, carbamoyl group and
amino group" include those substituted by an alkyl group, a cycloalkyl
group, an aryl group, an aralkyl group or a heterocyclic group, wherein
the alkyl group, the cycloalkyl group, the aryl group, the aralkyl group
and the heterocyclic group may be unsubstituted or substituted. The term
"silyl group" means a group of formula --SiR62R63R64,
wherein R62, R63 and R64 are independently of each other a
C1-C8alkyl group, in particular a C1-C4 alkyl group,
a C6-C24aryl group or a C7-C12aralkyl group, such as
a trimethylsilyl group. The term "siloxanyl group" means a group of
formula --O--SiR62R63R64, wherein R62, R63 and
R64 are as defined above, such as a trimethylsiloxanyl group.

[0057]The term "cycloalkyl group" is typically C5-C12cycloalkyl,
such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl,
cyclodecyl, cycloundecyl, cyclododecyl, preferably cyclopentyl,
cyclohexyl, cycloheptyl, or cyclooctyl, which may be unsubstituted or
substituted. The term "cycloalkenyl group" means an unsaturated alicyclic
hydrocarbon group containing one or more double bonds, such as
cyclopentenyl, cyclopentadienyl, cyclohexenyl and the like, which may be
unsubstituted or substituted. The cycloalkyl group, in particular a
cyclohexyl group, can be condensed one or two times by phenyl which can
be substituted one to three times with C1-C4-alkyl, halogen and
cyano. Examples of such condensed cyclohexyl groups are:

##STR00070##

in particular

##STR00071##

wherein R51, R52, R53, R54, R55 and

[0058]R56 are independently of each other C1-C8-alkyl,
C1-C8-alkoxy, halogen and cyano, in particular hydrogen.

[0059]Aryl is usually C6-C30aryl, preferably
C6-C24aryl, which optionally can be substituted, such as, for
example, phenyl, 4-methylphenyl, 4-methoxyphenyl, naphthyl, especially
1-naphthyl, or 2-naphthyl, biphenylyl, terphenylyl, pyrenyl, 2- or
9-fluorenyl, phenanthryl, anthryl, tetracyl, pentacyl, hexacyl, or
quaderphenylyl, which may be unsubstituted or substituted.

[0060]The term "aralkyl group" is typically C7-C24aralkyl, such
as benzyl, 2-benzyl-2-propyl, β-phenyl-ethyl,
α,α-dimethylbenzyl, ω-phenyl-butyl,
ω,ωdimethyl-ω-phenyl-butyl, ω-phenyl-dodecyl,
ω-phenyl-octadecyl, ω-phenyl-eicosyl or
ω-phenyl-docosyl, preferably C7-C18aralkyl such as
benzyl, 2-benzyl-2-propyl, β-phenyl-ethyl,
α,α-dimethylbenzyl, ω-phenyl-butyl,
ω,ω-dimethyl-ω-phenyl-butyl, ω-phenyl-dodecyl or
ω-phenyl-octadecyl, and particularly preferred
C7-C12aralkyl such as benzyl, 2-benzyl-2-propyl,
β-phenyl-ethyl, α,α-dimethylbenzyl,
ω-phenyl-butyl, or ω,ω-dimethyl-ωphenyl-butyl, in
which both the aliphatic hydrocarbon group and aromatic hydrocarbon group
may be unsubstituted or substituted.

[0061]The term "aryl ether group" is typically a C6-24aryloxy group,
that is to say O--C6-24aryl, such as, for example, phenoxy or
4-methoxyphenyl. The term "aryl thioether group" is typically a
C6-24arylthio group, that is to say S--C6-24aryl, such as, for
example, phenylthio or 4-methoxyphenylthio. The term "carbamoyl group" is
typically a C1-18-carbamoyl radical, preferably C1-8-carbamoyl
radical, which may be unsubstituted or substituted, such as, for example,
carbamoyl, methylcarbamoyl, ethylcarbamoyl, n-butylcarbamoyl,
tert-butylcarbamoyl, dimethylcarbamoyloxy, morpholinocarbamoyl or
pyrrolidinocarbamoyl.

[0063]Alkylaryl refers to alkyl-substituted aryl radicals, especially
C7-C12alkylaryl. Examples are tolyl, such as 3-methyl-, or
4-methylphenyl, or xylyl, such as 3,4-dimethylphenyl, or
3,5-dimethylphenyl.

[0065]Examples of a five or six membered ring formed by, for example,
R25 and R26, respectively are heterocycloalkanes or
heterocycloalkenes having from 3 to 5 carbon atoms which can have one
additional hetero atom selected from nitrogen, oxygen and sulfur, for
example

##STR00072##

which can be part of a bicyclic system, for example

##STR00073##

[0066]Possible substituents of the above-mentioned groups are
C1-C8alkyl, a hydroxyl group, a mercapto group,
C1-C8alkoxy, C1-C8alkylthio, halogen,
halo-C1-C8alkyl, a cyano group, an aldehyde group, a ketone
group, a carboxyl group, an ester group, a carbamoyl group, an amino
group, a nitro group or a silyl group.

[0067]If a substituent, such as, for example R7 occurs more than one
time in a group, it can be different in each occurrence.

[0068]The wording "substituted by G" means that one, or more, especially
one to three substituents G might be present.

[0069]As described above, the aforementioned groups may be substituted by
E and/or, if desired, interrupted by D. Interruptions are of course
possible only in the case of groups containing at least 2 carbon atoms
connected to one another by single bonds; C6-C18aryl is not
interrupted; interrupted arylalkyl or alkylaryl contains the unit D in
the alkyl moiety. C1-C18alkyl substituted by one or more E
and/or interrupted by one or more units D is, for example,
(CH2CH2O)1-9-Rx, where Rx is H or
C1-C10alkyl or C2-C10alkanoyl (e.g.
CO--CH(C2H5)C4H9),
CH2--CH(ORy')--CH2--O--Ry, where Ry is
C1-C18alkyl, C5-C12cycloalkyl, phenyl,
C7-C15-phenylalkyl, and Ry' embraces the same definitions
as Ry or is H; C1-C8alkylene-COO--Rz, e.g.
CH2COORz, CH(CH3)COORz, C(CH3)2COORz,
where Rz is H, C1-C18alkyl,
(CH2CH2O)1-9-Rx, and Rx embraces the definitions
indicated above; CH2CH2--O--CO--CH═CH2;
CH2CH(OH)CH2--O--CO--C(CH3)═CH2.

[0072]The compounds of formula I can be used in organic light emitting
diodes (OLEDs), especially as hosts for phosphorescent compounds.
Accordingly, the present invention also relates to an electroluminescent
device, comprising a compound of formula I. In a preferred embodiment the
electroluminescent device comprising a cathode, an anode, and
therebetween a light emitting layer containing a host material and a
phosphorescent light-emitting material wherein the host material is a
compound of formula I.

[0073]Suitably, the light-emitting layer of the OLED device comprises a
host material and one or more guest materials for emitting light. At
least one of the host materials is a compound comprising a compound of
formula I. The light-emitting guest material(s) is usually present in an
amount less than the amount of host materials and is typically present in
an amount of up to 15 wt % of the host, more typically from 0.1 to 10 wt
% of the host, and commonly from 2 to 8% of the host. For convenience,
the phosphorescent complex guest material may be referred to herein as a
phosphorescent material. The emissive layer may comprise a single
material, that combines transport and emissive properties. Whether the
emissive material is a dopant or a major constituent, emissive layer may
comprise other materials, such as dopants that tune the emission of the
emissive layer. The emissive layer may include a plurality of emissive
materials capable of, in combination, emitting a desired spectrum of
light.

Other Host Materials for Phosphorescent Materials

[0074]The host material useful in the invention may be used alone or in
combination with other host materials. Other host materials should be
selected so that the triplet exciton can be transferred efficiently from
the host material to the phosphorescent material. Suitable host materials
are described in WO0/70655; 01/39234; 01/93642; 02/074015; 02/15645, and
US20020117662. Suitable hosts include certain aryl amines, triazoles,
indoles and carbazole compounds. Examples of hosts are
4,4'-N,N'-dicarbazole-biphenyl (CBP),
2,2'-dimethyl-4,4'-N,N'-dicarbazole-biphenyl,
m-(N,N'-dicarbazole)benzene, and poly(N-vinylcarbazole), including their
derivatives.

[0075]Desirable host materials are capable of forming a continuous film.
The light-emitting layer may contain more than one host material in order
to improve the device's film morphology, electrical properties, light
emission efficiency, and lifetime. The light emitting layer may contain a
first host material that has good hole-transporting properties, and a
second host material that has good electron-transporting properties.

[0077]The emission wavelengths of cyclometallated Ir(III) complexes of the
type IrL3 and IrL2L', such as the green-emitting
fac-tris(2-phenylpyridinato-N,C2')iridium(III) and
bis(2-phenylpyridinato-N,C2')Iridium(II) (acetylacetonate) may be
shifted by substitution of electron donating or withdrawing groups at
appropriate positions on the cyclometallating ligand L, or by choice of
different heterocycles for the cyclometallating ligand L. The emission
wavelengths may also be shifted by choice of the ancillary ligand L'.
Examples of red emitters are the
bis(2-(2'-benzothienyl)pyridinato-N,C3')iridium(EI)(acetylacetonate)
and tris(1-phenylisoquinolinato-N,C)iridium(III). A blue-emitting example
is bis(2-(4,6-difluorophenyl)-pyridinato-N,C2)Iridium(III)(picolinat-
e).

[0083]In addition to suitable hosts, an OLED device employing a
phosphorescent material often requires at least one exciton or hole
blocking layers to help confine the excitons or electron-hole
recombination centers to the light-emitting layer comprising the host and
phosphorescent material, or to reduce the number of charge carriers
(electrons or holes). In one embodiment, such a blocking layer would be
placed between the electron-transporting layer and the light-emitting
layer. In this case, the ionization potential of the blocking layer
should be such that there is an energy barrier for hole migration from
the host into the electron-transporting layer, while the electron
affinity should be such that electrons pass more readily from the
electron-transporting layer into the light-emitting layer comprising host
and phosphorescent material. It is further desired, but not absolutely
required, that the triplet energy of the blocking material be greater
than that of the phosphorescent material. Suitable hole-blocking
materials are described in WO0/70655 and WO01/93642. Two examples of
useful materials are bathocuproine (BCP) and
bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (BAlQ).
Metal complexes other than Balq are also known to block holes and
excitons as described in US20030068528. US20030175553 describes the use
of fac-tris(1-phenylpyrazolato-N,C2)iridium(III) (Irppz) in an
electron/exciton blocking layer.

[0084]Embodiments of the invention can provide advantageous features such
as operating efficiency, higher luminance, color hue, low drive voltage,
and improved operating stability. Embodiments of the organometallic
compounds useful in the invention can provide a wide range of hues
including those useful in the emission of white light (directly or
through filters to provide multicolor displays).

General Device Architecture

[0085]The compounds of the present invention can be employed in many OLED
device configurations using small molecule materials, oligomeric
materials, polymeric materials, or combinations thereof. These include
very simple structures comprising a single anode and cathode to more
complex devices, such as passive matrix displays comprised of orthogonal
arrays of anodes and cathodes to form pixels, and active-matrix displays
where each pixel is controlled independently, for example, with thin film
transistors (TFTs).

[0086]There are numerous configurations of the organic layers. The
essential requirements of an OLED are an anode, a cathode, and an organic
light-emitting layer located between the anode and cathode. Additional
layers may be employed as more fully described hereafter.

[0087]A typical structure, especially useful for of a small molecule
device, is comprised of a substrate, an anode, a hole-injecting layer, a
hole-transporting layer, a light-emitting layer, a hole- or
exciton-blocking layer, an electron-transporting layer, and a cathode.
These layers are described in detail below. Note that the substrate may
alternatively be located adjacent to the cathode, or the substrate may
actually constitute the anode or cathode. The organic layers between the
anode and cathode are conveniently referred to as the organic EL element.
Also, the total combined thickness of the organic layers is desirably
less than 500 nm.

Substrate

[0088]The substrate can either be light transmissive or opaque, depending
on the intended direction of light emission. The light transmissive
property is desirable for viewing the EL emission through the substrate.
Transparent glass or plastic is commonly employed in such cases. The
substrate can be a complex structure comprising multiple layers of
materials. This is typically the case for active matrix substrates
wherein TFTs are provided below the OLED layers. It is still necessary
that the substrate, at least in the emissive pixilated areas, be
comprised of largely transparent materials such as glass or polymers. For
applications where the EL emission is viewed through the top electrode,
the transmissive characteristic of the bottom support is immaterial, and
therefore can be light transmissive, light absorbing or light reflective.
Substrates for use in this case include, but are not limited to, glass,
plastic, semiconductor materials, silicon, ceramics, and circuit board
materials. Again, the substrate can be a complex structure comprising
multiple layers of materials such as found in active matrix TFT designs.
It is necessary to provide in these device configurations a
light-transparent top electrode.

Anode

[0089]When the desired electroluminescent light emission (EL) is viewed
through the anode, the anode should be transparent or substantially
transparent to the emission of interest. Common transparent anode
materials used in this invention are indium-tin oxide (ITO), indium-zinc
oxide (IZO) and tin oxide, but other metal oxides can work including, but
not limited to, aluminum- or indium-doped zinc oxide, magnesium-indium
oxide, and nickel-tungsten oxide. In addition to these oxides, metal
nitrides, such as gallium nitride, and metal selenides, such as zinc
selenide, and metal sulfides, such as zinc sulfide, can be used as the
anode. For applications where EL emission is viewed only through the
cathode, the transmissive characteristics of the anode are immaterial and
any conductive material can be used, transparent, opaque or reflective.
Example conductors for this application include, but are not limited to,
gold, iridium, molybdenum, palladium, and platinum. Desired anode
materials are commonly deposited by any suitable means such as
evaporation, sputtering, chemical vapor deposition, or electrochemical
means. Anodes can be patterned using well-known photolithographic
processes. Optionally, anodes may be polished prior to application of
other layers to reduce surface roughness so as to minimize shorts or
enhance reflectivity.

Cathode

[0090]When light emission is viewed solely through the anode, the cathode
used in this invention can be comprised of nearly any conductive
material. Desirable materials have good film-forming properties to ensure
good contact with the underlying organic layer, promote electron
injection at low voltage, and have good stability. Useful cathode
materials often contain a low work function metal (<4.0 eV) or metal
alloy. One useful cathode material is comprised of a Mg:Ag alloy wherein
the percentage of silver is in the range of 1 to 20%, as described in
U.S. Pat. No. 4,885,221. Another suitable class of cathode materials
includes bilayers comprising the cathode and a thin electron-injection
layer (EIL) in contact with an organic layer (e.g., an electron
transporting layer (ETL)) which is capped with a thicker layer of a
conductive metal. Here, the EIL preferably includes a low work function
metal or metal salt, and if so, the thicker capping layer does not need
to have a low work function. One such cathode is comprised of a thin
layer of LiF followed by a thicker layer of Al as described in U.S. Pat.
No. 5,677,572. An ETL material doped with an alkali metal, for example,
Li-doped Alq, is another example of a useful EIL. Other useful cathode
material sets include, but are not limited to, those disclosed in U.S.
Pat. Nos. 5,059,861, 5,059,862 and 6,140,763.

[0091]When light emission is viewed through the cathode, the cathode must
be transparent or nearly transparent. For such applications, metals must
be thin or one must use transparent conductive oxides, or a combination
of these materials. Optically transparent cathodes have been described in
more detail in U.S. Pat. Nos. 4,885,211, 5,247,190, JP 3,234,963, U.S.
Pat. Nos. 5,703,436, 5,608,287, 5,837,391, 5,677,572, 5,776,622,
5,776,623, 5,714,838, 5,969,474, 5,739,545, 5,981,306, 6,137,223,
6,140,763, 6,172,459, EP1076368, U.S. Pat. Nos. 6,278,236 and 6,284,3936.
Cathode materials are typically deposited by any suitable method such as
evaporation, sputtering, or chemical vapor deposition. When needed,
patterning can be achieved through many well known methods including, but
not limited to, through-mask deposition, integral shadow masking as
described in U.S. Pat. No. 5,276,380 and EP0732868, laser ablation, and
selective chemical vapor deposition.

Hole-Injecting Layer (HIL)

[0092]A hole-injecting layer may be provided between anode and
hole-transporting layer. The hole-injecting material can serve to improve
the film formation property of subsequent organic layers and to
facilitate injection of holes into the hole-transporting layer. Suitable
materials for use in the hole-injecting layer include, but are not
limited to, porphyrinic compounds as described in U.S. Pat. No.
4,720,432, plasma-deposited fluorocarbon polymers as described in U.S.
Pat. No. 6,208,075, and some aromatic amines, for example, m-MTDATA
(4,4',4''-tris[(3-methylphenyl)phenylamino]triphenylamine). Alternative
hole-injecting materials reportedly useful in organic EL devices are
described in EP0891121 and EP1029909.

Hole-Transporting Layer (HTL)

[0093]The hole-transporting layer of the organic EL device contains at
least one hole-transporting compound such as an aromatic tertiary amine,
where the latter is understood to be a compound containing at least one
trivalent nitrogen atom that is bonded only to carbon atoms, at least one
of which is a member of an aromatic ring. In one form the aromatic
tertiary amine can be an arylamine, such as a monoarylamine, diarylamine,
triarylamine, or a polymeric arylamine. Exemplary monomeric triarylamines
are illustrated in U.S. Pat. No. 3,180,730. Other suitable triarylamines
substituted with one or more vinyl radicals and/or comprising at least
one active hydrogen containing group are disclosed in U.S. Pat. Nos.
3,567,450 and 3,658,520. A more preferred class of aromatic tertiary
amines are those which include at least two aromatic tertiary amine
moieties as described in U.S. Pat. Nos. 4,720,432 and 5,061,569. Such
compounds include those represented by structural formula

##STR00081##

wherein Q1 and Q2 are independently selected aromatic tertiary
amine moieties and G is a linking group such as an arylene,
cycloalkylene, or alkylene group of a carbon to carbon bond. In one
embodiment, at least one of Q1 or Q2 contains a polycyclic
fused ring structure, e.g., a naphthalene. When G is an aryl group, it is
conveniently a phenylene, biphenylene, or naphthalene moiety.

where Q3 and Q4 each independently represents a hydrogen atom,
an aryl group, or an alkyl group or Q3 and Q4 together
represent the atoms completing a cycloalkyl group; and Q5 and
Q6 each independently represents an aryl group, which is in turn
substituted with a diaryl substituted amino group, as indicated by
structural formula

##STR00083##

wherein Q7 and Q8 are independently selected aryl groups. In one
embodiment, at least one of Q7 or Q8 contains a polycyclic
fused ring structure, e.g., a naphthalene.

[0095]Another class of aromatic tertiary amines are the tetraaryldiamines.
Desirable tetraaryldiamines include two diarylamino groups, such as
indicated by formula (C), linked through an arylene group. Useful
tetraaryldiamines include those represented by formula

##STR00084##

wherein each Are is an independently selected arylene group, such as a
phenylene or anthracene moiety, n is an integer of from 1 to 4, and Ar,
Q9, Q10, and Q11 are independently selected aryl groups.
In a typical embodiment, at least one of Ar, Q9, Q10, and
Q11 is a polycyclic fused ring structure, e.g., a naphthalene. The
various alkyl, alkylene, aryl, and arylene moieties of the foregoing
structural formulae (A), (B), (C), (D), can each in turn be substituted.
Typical substituents include alkyl groups, alkoxy groups, aryl groups,
aryloxy groups, and halogen such as fluoride, chloride, and bromide. The
various alkyl and alkylene moieties typically contain from about 1 to 6
carbon atoms. The cycloalkyl moieties can contain from 3 to about 10
carbon atoms, but typically contain five, six, or seven ring carbon
atoms, e.g. cyclopentyl, cyclohexyl, and cycloheptyl ring structures. The
aryl and arylene moieties are usually phenyl and phenylene moieties.

[0096]The hole-transporting layer can be formed of a single or a mixture
of aromatic tertiary amine compounds. Specifically, one may employ a
triarylamine, such as a triarylamine satisfying the formula (B), in
combination with a tetraaryldiamine, such as indicated by formula (D).

[0097]When a triarylamine is employed in combination with a
tetraaryldiamine, the latter is positioned as a layer interposed between
the triarylamine and the electron injecting and transporting layer.
Illustrative of useful aromatic tertiary amines are the following:
1,1-Bis(4-di-p-tolylaminophenyl)cyclohexane,
1,1-bis(4-di-p-tolylaminophenyl)-4-phenylcyclohexane,
N,N,N',N'-tetraphenyl-4,4'''-diamino-1,1':4',1'':4'', 1'''-quaterphenyl
bis(4-dimethylamino-2-methylphenyl)phenylmethane,
1,4-bis[2-[4-[N,N-di(p-toly)amino]phenyl]vinyl]benzene (BDTAPVB),
N,N,N',N'-tetra-p-tolyl-4,4'-diaminobiphenyl,
N,N,N',N'-tetraphenyl-4,4'-diaminobiphenyl,
N,N,N',N'-tetra-1-naphthyl-4,4'-diaminobiphenyl,
N,N,N',N'-tetra-2-naphthyl-4,4'-diaminobiphenyl, N-phenylcarbazole,
4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB),
4,4'-bis[N-(1-naphthyl)-N-(2-naphthyl)amino]biphenyl (TNB),
4,4'-bis[N-(1-naphthyl)-N-phenylamino]p-terphenyl,
4,4'-bis[N-(2-naphthyl)-N-phenylamino]biphenyl,
4,4'-bis[N-(3-acenaphthenyl)-N-phenylamino]biphenyl,
1,5-bis[N-(1-naphthyl)-N-phenylamino]naphthalene,
4,4'-bis[N-(9-anthryl)-N-phenylamino]biphenyl,
4,4'-bis[N-(1-anthryl)-N-phenylamino]-p-terphenyl,
4,4'-bis[N-(2-phenanthryl)-N-phenylamino]biphenyl,
4,4'-bis[N-(8-fluoranthenyl)-N-phenylamino]biphenyl,
4,4'-bis[N-(2-pyrenyl)-N-phenylamino]biphenyl,
4,4'-bis[N-(2-naphthacenyl)-N-phenylamino]biphenyl,
4,4'-bis[N-(2-perylenyl)-N-phenylamino]biphenyl,
4,4'-bis[N-(1-coronenyl)-N-phenylamino]biphenyl, 2,6-bis(di-p-tolylamino)
naphthalene, 2,6-bis[di-(1-naphthyl)amino]naphthalene,
2,6-bis[N-(1-naphthyl)-N-(2-naphthyl)amino]naphthalene,
N,N,N',N'-tetra(2-naphthyl)-4,4''-diamino-p-terphenyl, 4,4'-bis
{N-phenyl-N-[4-(1-naphthyl)-phenyl]amino}biphenyl,
2,6-bis[N,N-di(2-naphthyl)amino]fluorine,
4,4',4''-tris[(3-methylphenyl)phenylamino]triphenylamine (MTDATA), and
4,4'-Bis[N-(3-methylphenyl)-N-phenylamino]biphenyl(TPD). A hole transport
layer may be used to enhance conductivity. NPD and TPD are examples of
intrinsic hole transport layers. An example of a p-doped hole transport
layer is m-MTDATA doped with F4-TCNQ at a molar ratio of 50:1 as
disclosed in U.S. Pat. No. 6,337,102 or DE10058578.

[0098]Another class of useful hole-transporting materials includes
polycyclic aromatic compounds as described in EP1009041. Tertiary
aromatic amines with more than two amine groups may be used including
oligomeric materials. In addition, polymeric hole-transporting materials
can be used such as poly(N-vinylcarbazole) (PVK), polythiophenes,
polypyrrole, polyaniline, and copolymers such as
poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) also called
PEDOT/PSS.

Fluorescent Light-Emitting Materials and Layers (LEL)

[0099]In addition to the phosphorescent materials, other light emitting
materials may be used in the OLED device, including fluorescent
materials. Although the term "fluorescent" is commonly used to describe
any light emitting material, in this case we are referring to a material
that emits light from a singlet excited state. Fluorescent materials may
be used in the same layer as the phosphorescent material, in adjacent
layers, in adjacent pixels, or any combination. Care must be taken not to
select materials that will adversely affect the performance of the
phosphorescent materials. One skilled in the art will understand that
triplet excited state energies of materials in the same layer as the
phosphorescent material or in an adjacent layer must be appropriately set
so as to prevent unwanted quenching. As more fully described in U.S. Pat.
Nos. 4,769,292 and 5,935,721, the light-emitting layer (LEL) of the
organic EL element includes a luminescent fluorescent or phosphorescent
material where electroluminescence is produced as a result of
electron-hole pair recombination in this region. The light-emitting layer
can be comprised of a single material, but more commonly consists of a
host material doped with a guest emitting material or materials where
light emission comes primarily from the emitting materials and can be of
any color. The host materials in the light-emitting layer can be an
electron-transporting material, as defined below, a hole-transporting
material, as defined above, or another material or combination of
materials that support hole-electron recombination. Fluorescent emitting
materials are typically incorporated at 0.01 to 10% by weight of the host
material. The host and emitting materials can be small non-polymeric
molecules or polymeric materials such as polyfluorenes and
polyvinylarylenes (e.g., poly(p-phenylenevinylene), PPV). In the case of
polymers, small molecule emitting materials can be molecularly dispersed
into a polymeric host, or the emitting materials can be added by
copolymerizing a minor constituent into a host polymer. Host materials
may be mixed together in order to improve film formation, electrical
properties, light emission efficiency, lifetime, or manufacturability.
The host may comprise a material that has good hole-transporting
properties and a material that has good electron-transporting properties.

[0100]Host and emitting materials known to be of use include, but are not
limited to, those disclosed in U.S. Pat. Nos. 4,768,292, 5,141,671,
5,150,006, 5,151,629, 5,405,709, 5,484,922, 5,593,788, 5,645,948,
5,683,823, 5,755,999, 5,928,802, 5,935,720, 5,935,721, and 6,020,078.

[0101]Metal complexes of 8-hydroxyquinoline and similar derivatives
(Formula E) constitute one class of useful host compounds capable of
supporting electroluminescence, and are particularly suitable for light
emission of wavelengths longer than 500 nm, e.g., green, yellow, orange,
and red.

##STR00085##

wherein M represents a metal; v is an integer of from 1 to 4; and ZZ
independently in each occurrence represents the atoms completing a
nucleus having at least two fused aromatic rings. From the foregoing it
is apparent that the metal can be monovalent, divalent, trivalent, or
tetravalent metal. The metal can, for example, be an alkali metal, such
as lithium, sodium, or potassium; an alkaline earth metal, such as
magnesium or calcium; an earth metal, such aluminum or gallium, or a
transition metal such as zinc or zirconium. Generally any monovalent,
divalent, trivalent, or tetravalent metal known to be a useful chelating
metal can be employed. ZZ completes a heterocyclic nucleus containing at
least two fused aromatic rings, at least one of which is an azole or
azine ring. Additional rings, including both aliphatic and aromatic
rings, can be fused with the two required rings, if required. To avoid
adding molecular bulk without improving on function the number of ring
atoms is usually maintained at 18 or less.

[0102]Illustrative of useful chelated oxinoid compounds are the following:

[0104]Preferred thin film-forming materials for use in forming the
electron-transporting layer of the organic EL devices of this invention
are metal chelated oxinoid compounds, including chelates of oxine itself
(also commonly referred to as 8-quinolinol or 8-hydroxyquinoline). Such
compounds help to inject and transport electrons and exhibit both high
levels of performance and are readily fabricated in the form of thin
films. Exemplary of contemplated oxinoid compounds are those satisfying
structural formula (E), previously described. Other electron-transporting
materials include various butadiene derivatives as disclosed in U.S. Pat.
No. 4,356,429 and various heterocyclic optical brighteners as described
in U.S. Pat. No. 4,539,507. Benzazoles satisfying structural formula (G)
are also useful electron transporting materials. Triazines are also known
to be useful as electron transporting materials. Doping may be used to
enhance conductivity. Alq3 is an example of an intrinsic electron
transport layer. An example of an n-doped electron transport layer is
BPhen doped with Li at a molar ratio of 1:1, as disclosed in U.S. Pat.
No. 6,337,102.

Deposition of Organic Layers

[0105]The organic materials mentioned above are suitably deposited by any
means suitable for the form of the organic materials. In the case of
small molecules, they are conveniently deposited through thermal
evaporation, but can be deposited by other means such as from a solvent
with an optional binder to improve film formation. If the material is
soluble or in oligomeric/polymeric form, solution processing is usually
preferred e.g. spin-coating, ink-jet printing. Dendrimer substituents may
be used to enhance the ability of small molecules to undergo solution
processing. Patterned deposition can be achieved using shadow masks,
integral shadow masks (U.S. Pat. No. 5,294,870), spatially-defined
thermal dye transfer from a donor sheet (U.S. Pat. Nos. 5,688,551,
5,851,709 and 6,066,357) and inkjet method (U.S. Pat. No. 6,066,357).

Encapsulation

[0106]Most OLED devices are sensitive to moisture or oxygen, or both, so
they are commonly sealed in an inert atmosphere such as nitrogen or
argon, along with a desiccant such as alumina, bauxite, calcium sulfate,
clays, silica gel, zeolites, alkaline metal oxides, alkaline earth metal
oxides, sulfates, or metal halides and perchlorates. Methods for
encapsulation and desiccation include, but are not limited to, those
described in U.S. Pat. No. 6,226,890. In addition, barrier layers such as
SiOx, Teflon, and alternating inorganic/polymeric layers are known
in the art for encapsulation.

[0107]Devices fabricated in accordance with embodiments of the invention
may be incorporated into a wide variety of consumer products, including
flat panel displays, computer monitors, televisions, billboards, lights
for interior or exterior illumination and/or signalling, fully
transparent displays, flexible displays, laser printers, cell phones,
personal digital assistants (PDAs), laptop computers, digital cameras,
camcorders, viewfinders, micro-displays, vehicles, theatre or stadium
screen, or a sign. Various control mechanism may be used to control
devices fabricated in accordance with the present invention, including
passive matrix and active matrix.

[0108]Various features and aspects of the present invention are
illustrated further in the examples that follow. While these examples are
presented to show one skilled in the art how to operate within the scope
of this invention, they are not to serve as a limitation on the scope of
the invention where such scope is only defined in the claims. Unless
otherwise indicated in the following examples and elsewhere in the
specification and claims, all parts and percentages are by weight,
temperatures are in degrees centigrade and pressures are at or near
atmospheric.

EXAMPLES

Example 1

##STR00086##

[0110]0.80 g of the starting iodide, 0.44 g of diphenylamine, 0.01 g of
copper iodide, 0.02 g of 1,10-phenanthroline and 0.53 g of sodium
hydroxide are added in this order to 10 ml of dry toluene under an
atmosphere of argon. The reaction mixture is heated at 125° C. for
one night. The precipitated product is filtered and re-crystallized in 20
ml DMF. 0.40 g of 90% pure product are obtained. The product is purified
by column chromatography on silica gel with toluene.

Example 2

##STR00087##

[0112]2a) To 12.0 g (32.8 mmol) 3,6-dibromo-phenanthrene-9,10-dione in 300
ml water free ethanol 2.36 g (39.3 mmol) ethanol diamine are added. The
reaction mixture is refluxed under nitrogen for 8 h. 500 ml glacial
acetic acid are added and the reaction mixture is refluxed for additional
9 h under air and cooled to 25° C. The product is filtered off and
washed with ethanol (melting point: 278.0-282.0° C.).

##STR00088##

[0113]2b) To 3.00 g (7.73 mmol) of the product of example 2a in 60 ml
toluene 1.60 g (16.6 mmol) sodium tert-butylate are added. The reaction
mixture is degassed with argon. 87 mg (0.39 mmol) palladium (II) acetate
are added. The reaction mixture is degassed with argon. 156 mg (0.77
mmol) tri-tert-butylphosphine are added. A degassed solution of 5.26 g
(24.0 mmol) N-phenyl-1-naphthylamine in 15 ml toluene is added. The
reaction mixture is stirred for 19 h at 90° C. under argon. The
reaction mixture is filtered on silica gel with toluene. The solvent is
removed in vacuum and the product is crystallized from diethyl ether
(melting point: 228-230° C.).

Example 3

##STR00089##

[0115]The reaction is carried out according to example 2b except that 4.36
g (11.2 mmol) of the product of example 2b and N-diphenyl amine are used
(melting point: 206° C.).

Example 4

##STR00090##

[0117]4a) To 20.0 g (54.6 mmol) 2,7-dibromo-phenanthrene-9,10-dione in 300
ml water free ethanol 3.94 g (65.6 mmol) ethanoldiamine are added. The
reaction mixture is refluxed under nitrogen for 4 h. 500 ml glacial
acetic acid are added and the reaction mixture is refluxed for additional
30 h under air and is cooled to 25° C. The product is filtered
off, washed with water and decocted in glacial acetic acid and 2 times in
methyl ethyl ketone (melting point: 176.0-179.0° C.).

##STR00091##

[0118]4b) The synthesis is carried out in analogy to example 2b. The
product has a melting point of 177° C.

Example 5

##STR00092##

[0120]The synthesis is carried out in analogy to example 2b. The product
has a melting point of 266.0-267.0° C.

[0133]10b) The synthesis is carried out in analogy to example 2b. The
product has a melting point of 193.0-195.0° C. (glass transition
point 153° C.).

Example 11

##STR00101##

[0135]The synthesis is carried out in analogy to example 2b. The product
has a melting point of 350° C.

Example 12

##STR00102##

[0137]The synthesis is carried out in analogy to example 2b. The product
has a melting point of 290° C.

Application Example 1

[0138]Device fabrication: Prior to device fabrication, indium tin oxide
(ITO) on glass is patterned as 2 mm wide stripes (sheet resistance
20Ω/square). The substrates were cleaned by sonication in acetone,
isopropanol and water for 15 minutes in each solvent. After that, the
substrates are dried with a nitrogen steam and treated by O2 vacuum
plasma for 5 minutes. Organic layers of the OLEDS are sequentially
deposited by thermal evaporation from resistively heated ceramic
crucibles at a base pressure of 2×10-7 Torr, at 2A/s. Host and
dopant were co-evaporated from different sources to form a thin film of
20 nm thickness. The evaporation rate of each single component source was
controlled by a thickness monitor (Inficon) close to the substrate or to
the source. All the devices were measured in a nitrogen glove box,
immediately after fabrication.

[0139]Current-voltage and optical measurements were carried out with a
Botest equipment. Electroluminescent spectra were measured with an Ocean
Optic spectrometer.

[0140]An OLED is prepared having the following structure from the anode to
the cathode: 60 nm of a hole injection layer, such as NHT-5 of Novaled
AG, using 10 nm of an improved hole transport layer, such as NHT5:NDP2 of
Novaled AG, 20 nm of 4,4'-bis[N-1-naphthyl)-N-phenylamino]-biphenyl
(α-NPD), 20 nm of aluminum (III) bis(2-methyl-8-quinolato)
4-phenyl-phenolate (BAlq) doped with 15 wt % of compound obtained in
Example 3c/10 nm of BAlq acting as hole blocking layer, 60 nm of an
improved electron transport layer, such as NET-5:NDN-1 from Novaled, and
100 nm of aluminium as top electrode.